This invention relates to an applicator useful in the application of protective coatings and sealants to ship hulls and other structures under water.
The application of protective coatings to ship hulls, and/or crack repair compounds for repairing cracks therein can be accomplished by dry docking the ship but this is an expensive practice not always practical with large ships and also a practice which cannot be employed in the repair or maintenance of other underwater structures such as oil drilling platforms, pipes, bridges and dams.
So, in many cases, divers apply the protective coating under water. This latter methodology, wherein the divers use a brush or a trowel and a separate container of the protective coating compound is problematic since the protective coating often disintegrates and breaks away from the application tool resulting in a loss of product, decreased transfer efficiency, and contamination of the water affecting diver visibility and the release of toxic materials into the water which can harm the diver and marine life.
The practice of using a brush or a trowel and a separate container of the protective coating or sealing compound also makes it very difficult to apply a neat thin film of the coating material under water.
It is therefore an object of this invention to provide an applicator for applying protective coatings, crack repair compounds, and other compounds to structures under water such as ship hulls, oil drilling platforms, pipes, bridges and dams.
It is a further object of this invention to provide such an applicator which eliminates the expense and impracticality of dry docking a ship.
It is a further object of this invention to provide such an applicator which prevents the disintegration and/or coagulation of the coating compound during application.
It is a further object of this invention to provide such an applicator which increases the transfer efficiency of applying a protective coating to an underwater structure and reduces product loss or waste.
It is a further object of this invention to provide such an applicator which reduces contamination of the water which would otherwise affect a diver""s visibility and result in the release of toxic materials into the water which could harm the diver and marine life.
This invention results from the realization that the difficulty, inexactness, and the other problems (such as loss of coating material and contamination of the water) associated with prior art methods of applying a protective coating underwater to, for example, the hull of a ship, can be overcome with a special syringe or pressurized type applicator with a nozzle end opening which incorporates a leading wiper and an edge seal for preventing loss and/or coagulation of the protective coating material, and also by an integrated spatula which finally spreads and smooths the protective coating and which also simultaneously applies pressure to better adhere the protective coating. The combination of the syringe and the nozzle provides a controlled volumetric release of the coating material.
This invention features a protective coating, underwater applicator including a housing for receiving an underwater protective coating compound; a nozzle on a distal end of the housing with an end opening for applying the protective coating; a spatula extending from one portion of the end opening for spreading the protective coating; and a seal disposed about a substantial portion of the end opening for preventing the loss or coagulation of the protective coating.
The spatula or blade is typically rigid, smooth, and has a sharp edge and the seal extends over the edges of the blade. In one embodiment, the end opening is elongated (i.e., rectangular), the blade extends from one lengthy side of the opening, and the wiper extends along the opposite side. Edge seals are disposed on the edges of the opening.
In the preferred embodiment, a pivotable joint connects the nozzle with the housing. The seal is preferably made of an elastomeric material which does not react with the protective coating compound. In one embodiment, the housing includes two chambers, one chamber for resin and one chamber for a curing agent. In either embodiment, a plunger, receivable in the housing, urges the protective coating out through the nozzle.